1. Field of the Invention
This invention relates to a hand pressure device to diminish a gag reflex response or to normalize a hypersensitive gag reflex response.
2. Description of the Related Art
The gag reflex regularly interferes with many medical procedures, more particularly, dental procedures. Most dental patients have suffered from the gag reflex when X-ray films or mold plaster is placed in the back of their mouth. As most victims know, the impulse to gag is uncontrollable and makes some dental procedures intolerable. This stimulation of the gag reflex can be a stressful time for the patient and the dentist. It can lead to delay of treatment where, for example, the patient is not able to complete X-ray or crown fitting procedures. The fear of discomfort and embarrassment from gag reflex keeps many patients from receiving regular dental care. Still other patients are not even able to adequately perform proper oral hygiene due to gagging, even during tooth brushing.
The gag reflex protects the airway against the entrance of unwanted material and triggers the contraction of the superior laryngeal muscles. In general the neurologic pathway for the gag reflex response involves the glossopharyngeal nerve (CN IX) which sends projection fibers from the posterior one-third of the oral cavity to the nucleus tractus solitarius (NTS) of the medulla. Information from the NTS then sends signals to the nucleus ambiguus (NA), which activates the vagal (CN X) efferent fibers to produce the specific motor response. Despite this rudimentary understanding of the gag reflex response pathway, the specific neurologic underpinnings are poorly understood.
Previous study results indicated that a typical gag response is triggered in the posterior one-third of the oral cavity within one of five trigger zones (Bassi G S, Humphris G M, Longman L P, J. Prosthet. Dent. 2004, v. 91, pp. 459-467). The five trigger zones are the anterior and posterior faucial pillars, the base of the tongue, the palate, the uvula and the posterior pharyngeal wall.
There is no clear definition of a hypersensitive gag reflex in a neurologically intact person. Instead, the description of a hyper gag reflex can be divided into two categories: The force of the motor response and the place of sensory stimulation.
The most common description involves the force of motor response. They include severely pulling away from tactile stimulation (Leder S B., Head Neck 1996, v. 18: pp. 138-141), spasms of the pharynx (Bassi G S, Humphris G M, Longman L P, J. Prosthet. Dent. 2004, v. 91, pp. 459-467) or a combination of reflex responses with both gagging and some aspect of the emetic response (Bassi G S, Humphris G M, Longman L P., J. Prosthet. Dent. 2004, v. 91, pp. 459-467; Kramer R B, Braham R L., ASDC 1977, v. 44, pp. 111-116; Miller A J., Crit. Rev. Oral Biol. Med. 2002, v. 13, pp. 409-425).
Another description of the hypersensitive gag reflex refers to the place of sensory stimulation, specifically where the gag reflex response is triggered. Historical reports of hypersensitive gagging incidents described people who triggered a gag reflex in the anterior or middle portions of the oral cavity during tooth brushing, while shaving, or after a touch to the face (Landa J S. Practical full denture prosthesis, New York: Dental Items of Interest Publishing Co., Inc., 1947, pp. 268-279; Murphy W. M., J. Prosthet. Dent. 1979, v. 42, pp. 145-148). Recently, gag reflex responses to non-oral body parts and regions within the anterior oral cavity have been documented in a group of children 3 to 18 months of age who had persistent feeding delays (Scarborough D R, Boyce S, McCain G, Oppenheimer S, August A, Neils-Strinjas J., Dev Med Child Neurol 2006, v. 48, pp. 460-464).
A hypothetical model of the specific neurologic cause of a hypersensitive gag reflex response has been proposed to explain the aberrant response to touch in regions other than the posterior one-third of the oral cavity in a group of orally deprived infants (Scarborough D. R., Isaacson L. G., Clin. Anat. 2006, v. 19, pp. 640-644). Based on this theory, ‘transient’ tactile connections between the touch sensory fiber tracts and the nucleus tractus solitarius (NTS) are present at birth via an inhibitory interneuron. The activity of the transient fibers diminishes shortly after birth as a result of swallowing during feedings. In a hypersensitive gag reflex response situation these transient fibers fail to retract and consequently result in continued stimulation of the NTS with touch to areas other than the posterior one-third of the oral cavity.
Attempts have been made to diminish the gag reflex response within clinical settings. Early interventions included swabbing patients' mouths with diluted cocaine; using distraction techniques; asking patients to use willpower (Landa J. S., Practical full denture prosthesis, New York, Dental Items of Interest Publishing Co., Inc., 1947, pp. 268-279); excising their uvulas (Kramer R B, Braham R L, ASDC 1977, v. 44, pp. 111-116); voluntarily increasing respiration (Chaffee R B, Zabara J, Tansy M F, J. Dent. Res. 1970, v. 49, pp. 572-575); holding their breath (Kramer R B, Braham R L, ASDC 1977, v. 44, pp. 111-116); hypnosis (Bartlett K A, Am. J. Clinical. Hypn. 1973, v. 1, pp. 54-56); and relaxing with hypnosis (Murphy W M, J. Prosthet. Dent. 1979, v. 42, pp. 145-148). Behavior modification, suggestion, systematic desensitization, sensory flooding and medications also have been explored (Bassi G S, Humphris G M, Longman L P., J. Prosthet. Dent. 2004, v. 91, pp. 459-467; Kramer R B, Braham R L., ASDC 1977, v. 44, p. 111-116; Neumann J K, J. Prosthet. Dent. 2001, v. 85(3), pp. 305).
Acupuncture points on the ear (Fiske J, Dickinson, C., Br. Dent. J. 2001, v. 190(11), pp. 611-613) or forearm (Lu D P, Lu G P, Reed J F, Gen. Dent. 2000, v. 48(4), pp. 446-452), can control the gag reflex effectively during dental treatments. Combinations of acupuncture and hypnosis were recommended to treat hypersensitive gag reflex responses during long-term therapies (Eitner S, Wichmann M, Holst S, J. Clin. Exp. Hypn. 2005, v. 53(1), pp. 74-86; Eitner S., Wichmann M., Holst S, J. Clin. Exp. Hypn. 2005, v. 53, pp. 60-73). Although this combination treatment may alleviate hyperactive gag reflex responses, complications may arise and specialized training or teams would be needed. Moreover, the invasive nature of the combination technique is undesirable for many patients. For most dentists and other medical practitioners, a less invasive approach, such as acupressure, would be an attractive alternative. However, even acupressure may require specialized training for it to be effective.
One brief clinical report has indicated that a pressure point on the chin would be effective for diminishing the gag reflex responses. However, no additional study was done to evaluate this pressure point (Vachiramon A, Wang W C, J. Prosthet. Dent. 2002; v. 88(2), p. 236).
In a study of abnormal physiological response to touch among children with persistent feeding difficulties, researchers found a link between feeding difficulties in children and abnormal response to touch using graded firm pressure (Scarborough D. R., Boyce S., McCain G., Oppenheimer S., Dev. Med. Child Neurol. 2006, v. 48(6), pp. 460-464). These abnormal responses included gagging and/or state changes at the anterior portion of the oral cavity or on non-oral parts of the body. From the results of the study, the researchers developed a published theoretical model to explain these abnormal responses (Scarborough D. R. & Isaacson, L. G., Clinical Anatomy, 2006, v. 19, pp. 640-644). According to this theoretical model, these abnormal response patterns have aberrant neurologic connections within the nucleus tractus solitarius of the brainstem.